Ampath accounts reconcilaition is shocking, charging a patient incorrectly

There is something seriously wrong with Ampath and I need to report. My mum went for tests to Ampath in Feb 2021. She is a pensioner. The first statement given to me was paid in full by me on 24 March for R1258. The invoice was provided by Ampath,(Venesha), my son went to collect it, and I did an EFT immediatley. After paying this I sent proof of payment and spoke to Craig, *** and Venesha *** and they confirmed all is in order.

Then a few days ago I received an email for the outstanding R83.00. When I called in to ask why is this outstanding I was told the additional amount was included because my mother was on medical aid. My mother started medical aid with Bonnitas in Feb so as per medical aid rules she only became an active member in April 2021. She should not have been put in as a medical aid member in Feb, at that point she was a cash patient. What irritates me now is that I paid the outstanding R83. 00 and am still being threatened with legal action. What is wrong with Ampath????. All accounts are paid for in full.